Increasing environmental requirements have resulted in the coatings industry developing new coating systems which are less polluting than conventional solvent-based (10-25% solids) finishes. Typical of such new systems are high solids coatings. These can have solids contents in excess of 80%.
In an attempt to reach such high level of solids at acceptable spray viscosities, resin manufacturers initially used low molecular weight, liquid resins in high solids formulations. However, the liquid nature of the resins led to problems of sag, dirt pick-up and sticky overspray, even after most of the carrier solvent(s) had evaporated. Typical of such liquid resins are those based on dimethylcyclohexane dicarboxylate and ethylene glycol.
This invention provides new compositions of matter for use in high solids coating formulations. The new compositions give coatings having good drying characteristics and good sag resistance, while also maintaining good solubility in the commonly used solvents. Solids levels of the final formulation in excess of 60 wt. % can be obtained.